Norske Skog's Tasman mill in Kawerau. Photo: Norske Skog Freshwater campaigner Tiipene Marr, of Ngāti Rangitihi, said owner Norske Skog should have to produce an environmental audit before it leaves. The Norwegian company said it was aware of the environmental matters, and would meet all its obligations. Marr and his family used to call the river the "black drain" - now they call it the "brown drain". "The whole Tasman site is totally contaminated," Marr said. "It's been running for 66 years, polluting our river and polluting our people." Marr said in the past workers got sick from exposure to Tasman mill contaminants, and he said he watched as diggers buried chlorine-contaminated sludge in nearby forests.